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INA148: CM range with single supply

Joe DiBartolomeo
Expert 3125 points

Part Number: INA148

Hi All,

One of my customer is using the INA148 in single supply 12V application, Vref=0V.

What is the CM range, specifically low-limit common-mode input voltage?

Also any issue with the output swinging up to 10.5V.

Thanks,

Regards,

Joe

  • 0
    TI__Genius 10850 points

    Hi Joe,

    Thanks for your post. I can help you.

    When determining the boundary plot for the INA148, we have to analyze the nodes right at the input and output of the amplifier. On a 12V single supply, the output swing of this amplifier is 0.25V to 11V (as shown in the datasheet – Voltage Output). The transfer function for this device is Vout = Vd + Ref. Your customer has set Ref to 0V. So the differential voltage = output swing. The voltages seen right at the input of the amplifier (marked by a red circle the circuit below) must be between 0.25V to 11V for linear operation. By doing this, we can calculate the input common mode voltage range for this particular setup to be 5V to 200V.